Aluminum alloy and process of making same.



- num and be praoticall free from the defects I UNITED sT TEs PATENT OFFICE;

LEVI S. GARDNER, OF DETROIT, MICHIGAN.

ALUMINUM ALLOY AND PROCESS OF MAKING SAME.

No Drawing To all whom it may concern:

Be it known that I, LEVI- S. GARDNER, a citizen of the United States, residing at Detroit, county of Wayne, State of Michigan, have invented a certain new and useful Improvement in Aluminum Alloys and Processes of Making Same, and declare the following to be a full, clear, and exact description ofthe same, such as will enable others skilled in the art to which it pertains to make and use the same.

While aluminum alloys have many very desirable characteristics, they possess but lit tle tensile strength, arebrittle, cannot be bent, and present a ragged surface when machined unless operated upon slowly and carefully Many efforts have been made to produce an aluminum alloy which will be free from these defects but, so far as I am aware, with but little success.

The object of the present invention is to produce an aluminum alloy which shall retain all of the good characteristics of alumiheretofore enumerate 'In producing my new alloy I have discovered that the desired results can apparently be obtained only by following a particular process or method and therefore, viewed in one of its aspects, my invention may be said to comprise the discovery of a novel process of producing an aluminum alloy.

I have found that an alloy of aluminum, copper, tin and a small amount of manganese gives a metal which has greater tensile strength than any aluminum alloy of which I am aware, can be bent without breaking, can be machined at twice the cutting speed of the best previous alloy and without employing an oil or other bath, and when machined will present a smooth untorn and unpittedsurface just as one expects to find in a piece of machined brass or steel. Furthermore, the machined surface will remain-bright for an indefinite time, whereas the surface of the usual alloys will soon become dull-and gray.

The alloy may be made harder and also "somewhat cheaper by the addition of zinc.

Specification of Letters Patent.

I have also found small quantities of iron in tested samples but do not know definitely whether or not this is necessary. If the iron is necessary, it is present in, such small quanproportions, given, the proportions being by weight: aluminum 78, tin 10, copper 4, zinc 8, manganese .05, and iron .07.

Patented Oct. 8, 1 918. Application filed January 11, 1918. Serial No. 211,397. I

I make the alloy as follows: first a metal composed of aluminum, 5 parts, manganese bronze, 7 parts, and zinc, 6 parts is produced; the manganese bronze containing about fifty per cent. of copper and forty per cent. of zinc; and the final alloy is then produced by mixing together aluminum, tin,

and this preliminary composition metal in approximately the proportions, by weight, aluminum, 73, tin, 9, and the composition metal 18.

While I have given only what I believe to be the best formula and what I believe to be the best process for producing my improved alloy, I do not desire to be limited to the exact proportions or details thus specified, but intend to cover all formulae and methods of producing the same which will come within the terms of the definitions of my lnvention or discovery constituting the appended claims.

I claim: 1. An aluminum'alloy consisting of aluminum', copper, tin and manganese.

2. An aluminum alloy consisting of aluminum, zinc, copper, tin and manganese.

.3. An aluminum alloy containing the following in approximately the "proportions given: aluminum 78 copper, 4; tin, 10;

lowing in approximately the proportions given: aluminum, 78; copper, 4; tin. 10; zinc, 8; manganese .05.

v 5. The method of producing an aluminum alloy which con'sists in forming a composition of aluminum, manganese bronze, and

zinc; and then melting together a quantity of said composition metal, tin and aluminum.

6. The method of producing an aluminum 5 alloy containing copper, tin and manganese:

Which consists in formlng a composition,

metal of copper, aluminum and manganese;

and then melting a quantity of this composition metal with a larger quantity of aluminum and a quantity of tin.

In testimony whereof, I sign this specification.

LEVI S. GARDNER. 

